克服的過去式和過去分詞

beg (請求) begging begged begged

clap (拍掌) clapping clapped clapped

drop (落下) dropping dropped dropped

hop (跳) hopping hopped hopped

knit (編織) knitting knitted knitted

pin (扣住) pinning pinned pinned

rub (摩擦) rubbing rubbed rubbed

slip (滑跌) slipping slipped slipped

step (踏) stepping stepped stepped

stop (停止) stopping stopped stopped